British Prime Minister Tony Blair and Irish Prime Minister John Bruton announced the understanding after a meeting on the fringes of the UN environmental summit in New York.

"It's possible we have the basis of a way forward. But . . . this has got to be agreed with all the other parties," said Blair.

Bruton said it creates conditions for movement in multi-party peace talks in Belfast. He said all possible clarification had been provided to Sinn Fein, the political wing of the IRA, which must choose between political action and violence.